1. Field of the Invention
The invention relates to a solar cell and method of manufacturing a solar cell including a plurality of fine line-shaped electrodes that are formed on a photoelectric conversion body.
2. Description of Related Art
Sunlight energy is a clean energy and can be supplied inexhaustibly. Solar cells are capable of converting sunlight energy directly into electric energy, and hence are expected to provide a new energy source from sunlight.
A typical solar cell includes: a photoelectric conversion body configured to receive light and thus generate photogenerated carriers; and a plurality of fine line electrodes configured to collect the photogenerated carriers generated by the photoelectric conversion body. The fine line electrodes are formed by printing a conductive paste onto the photoelectric conversion body by such printing methods as screen printing and offset printing.
In a method that has been proposed to form the fine line electrodes, a conductive paste is printed by the screen printing method repeatedly so that paste prints are laid over one another (see Japanese Patent Application Publication No. Hei 11-103084). According to this method, the fine line electrodes have flat surfaces. So, even use of a highly resistive conductive paste, which is typically used under low-temperature environments, does not cause an increase in the electric resistance of each of the fine line electrodes.
The conductive paste printed on the photoelectric conversion body is so flowable that the conductive paste bleeds and spreads on the photoelectric conversion body. This bleeding and spreading of the conductive paste on the photoelectric conversion body increases the width of the fine line electrodes thereby reducing the light receiving area of the photoelectric conversion body.
This problem is more likely to occur when a plurality of bumps are formed on the surface of the photoelectric conversion body to improve the light-absorbing efficiency by the photoelectric conversion body. Specifically, the conductive paste bleeds and spreads along the spaces located between these bumps (i.e., along the valley-like portions).